The invention relates to a tank insert with a sensor unit, monitoring the tank internal pressure in particular, with the features of a sensor of internal tank pressure with connecting means, these being sealed off by dealing means and held by fastening means within a receptacle of the tank insert.
These features are known from German patent document DE 44 23 095 A1. According to this patent, a sensor receptacle in the shape of a cup and open to the interior of the tank is provided in a holder of a tank insert, with a pressure sensor inserted into the sensor receptacle. The sensor abuts a shoulder of the sensor receptacle by an annular seal and is secured therein by means of a clamping ring. The sensor receptacle is closed off on the outside by a cover which includes among other things a plug projection for the electrical contacts of the sensor.
There is a need for improvement in the mass production of this sensor unit. In particular, previously different parts such as the sensor itself (pressure measuring cell), seals, and retaining means can be assembled on the assembly line and the state of the sealing of the sensor receptacle and the correct function of the sensor unit can only be tested after the tank insert has been completely assembled. The time required on the assembly line and the probability of defects are relatively high because of the large number of operations.